Abstract
The characteristics of color vision have been mostly investigated with detection and discrimination tasks. Figure segregation by colors should be investigated as well to understand color vision working in multi-colored natural scenes. In this study we aimed to know how figure segregation was achieved by differences of color distributions in multi-colored textures. We used the texture as a stimulus, which composed of many multi-colored pieces with random shapes. The texture stimulus consisted of the test and the background region. We selected the colors of the pieces in the test and background region from different color distributions. These color distributions were either of spheres or of lines of certain directions in a color space. We measured thresholds for distance of shift of the test from the background distribution in the four chromatic directions in the color space. Thresholds of direction difference between the two line color distributions were also measured. The results showed that the thresholds of distance were higher with decreasing durations from 35 to 100ms, which was consistent with color discrimination threshold measured in an uniform field. However, the thresholds were different across shift directions, which could not be explained by the color discrimination mechanism.